Field of the Invention
The present disclosure generally relates to measuring and, more particularly, to a measuring apparatus, measuring method, lithography apparatus, article manufacturing method, and to a technique for measuring positions of shot regions formed on a substrate.
Description of the Related Art
To manufacture a device (an article) such as a semiconductor device, a lithography apparatus (e.g., an exposure apparatus) forms a pattern (a latent image pattern in a resist or a pattern of the resist) on a substrate. As the pattern to be formed becomes finer, the lithography apparatus needs to measure the position of the pattern on the substrate with higher accuracy, to superimpose the pattern on a pattern (a shot region) that has been already formed on the substrate.
In conventional measurement, an apparatus measures a position of partial shot region groups (sample shot region groups) of shot regions that have already been formed on a substrate, and determines a coefficient of a linear regression equation for the measured position. This regression equation is a linear (simple) equation for a position (X and Y coordinates) in design of each shot. Further, as for a leading substrate in the same lot, the apparatus determines an offset amount relative to a position of each shot obtained by this regression equation, and creates a table of this offset amount. To determine this offset amount, the apparatus measures shot regions except the sample shot region group. This table is used for other substrates included in the same lot, to omit measurement of shot regions except the sample shot region, so that overlay precision becomes compatible with throughput (see Japanese Patent Application Laid-Open No. 2003-086483).
Further, as for other substrates included in the same lot, there is a known method to determine if there is a need for updating the table based on a variation amount of the offset amount, and to update the table when there is such a need (International Publication WO2005/053007).
Manufacturing a device includes a lamination process of extracting a layer of a substrate formed through a lithography process, and laminating this layer with a different substrate such as a glass substrate. The substrate that has undergone such a lamination process may be further subjected to a lithography process. A pattern (a shot region) on the layer laminated with the different substrate in this laminating process may have large deformation. Therefore, the sample shot region group may include a shot region having deformation. In this case, the method of Japanese Patent Application Laid-Open No. 2003-086483 cannot achieve overlay within a tolerance, regardless of whether it is appropriate to apply the offset amount of the table, even if a pattern is formed based on the position of each shot region determined from the obtained regression equation. In addition, it is difficult to increase reproducibility of extraction or lamination of the substrate and therefore, the coefficient of the above-described regression equation may greatly vary depending on the substrate in the same lot. For this reason, when the method of International Publication WO2005/053007 is applied, the table is frequently updated, which is disadvantageous in terms of throughput of the lithography apparatus.